WO2007020938A1 - Suspension arm for vehicle - Google Patents

Abstract

A suspension arm for a vehicle, comprising an arm body (1) having a main plate body (2) press-molded to form the main part of the arm body and having a short cylindrical part (EB) integrally continued therewith at its one end by burring process and a reinforcement plate (H) stacked on one of the upper and lower surfaces of the main plate body (2) for reinforcing the main plate body (2). The reinforcement plate (H) comprises an eye-like head part (Ha) formed in a circular ring shape and arranged coaxially with the short cylindrical part (EB) and a tail part (Hb) integrally extending from the eye-like head part (Ha) along the longitudinal direction of the main plate body (2). The reinforcement plate is formed of a single plate material larger in thickness than the main plate body (2), at least the tail part (Hb) is welded to the main plate body (2), and a bush press-fitting part (P1) is formed by the inner peripheral surface of the eye-like head part (Ha) and the inner peripheral surface of the short cylindrical part (EB). Thus, since the cross sectional area of the transient portion of the arm body from the bush press-fitting part to the arm body can be sufficiently secured, a rigidity required for the transient portion can be easily secured, and the strength of the arm can be increased without increasing the outer peripheral space of the bush press-fitting part.

Description

 Specification

 Vehicle suspension arm

 Technical field

 The present invention relates to a vehicle suspension arm having an arm body made of a metal plate.

 Background art

 [0002] A suspension arm for a vehicle including an arm body made of a metal plate and a bush press-fit portion provided at one end of the arm body and capable of press-fitting a bush, for example, constitutes an arm body. Rings that are integrally connected to each end of the upper and lower plate bodies Each inner peripheral part of the plate-like upper and lower end plates is burring inward to form a pair of upper and lower inner peripheral flanges However, there has already been proposed an inner peripheral surface of these inner peripheral flanges as a bush press-fit surface (see, for example, FIG. 4 of Patent Document 1 below).

[0003] In this proposal, the pair of upper and lower inner peripheral flanges have their front end faces but the outer peripheral portions of the upper end plate and the lower end plate are connected to the inner peripheral flange on the inner side. Each pair of upper and lower outer peripheral flanges are bent inward so as to be substantially inward and face each other with a gap between them, so that the bush press-fit part has sufficient rigidity and strength equivalent to the collar. In addition, since there is no weld between the lower end plates, there is no need for a lap for welding, and the arm end shape can be miniaturized as much as possible. .

[0004] By the way, a suspension arm for a vehicle, in particular, an arm main body having one end connected to the vehicle body side and the other end connected to the wheel side, and a damper straddling an intermediate portion of the arm main body with a gap therebetween. A suspension arm having a structure that includes a bush support member for press-fitting and supporting a bush connected to a fork-like lower end portion via a connection pin, and a drive shaft passes through the gap is conventionally known. In the suspension arm of this structure, there is a space above and below the intermediate part that serves as the damper support part of the arm body to avoid interference with the drive shaft and the protective boot surrounding the joint part. On the side to avoid interference with fully steered or fully bumped wheels. The installation space for the arm body intermediate part is considerably limited because it is necessary to secure each of the chassis, and the arm part intermediate part also has high strength because the large damper support load acts on it. It is necessary to configure with high rigidity.

 [0005] In order to satisfy all of these requirements with force, for example, when a suspension arm is manufactured by forging as shown in FIG. 28 (a), the weight is increased and the cost is increased. There's a problem. In order to solve this problem, a suspension arm is already formed by pressing a metal plate to form a suspension arm. In such cases, the cross-sectional shape of the middle part of the arm body that is the damper support part is large. Inconvenient in that it is difficult to cope with diversifying vehicle needs in recent years (for example, increasing wheel wheel diameter, increasing engine output, increasing the size of the drive shaft, etc.), which causes significant restrictions on applicable models. It was hot.

 [0006] Further, as an improved structure of the suspension arm of the plate, for example, as shown in FIG. 28 (b), a cylindrical support is used as a bush support member for supporting a damper lower end support bush at an intermediate portion of the arm body. A structure was proposed in which this sleeve was welded to both side walls of the middle part of the arm body, but with this proposed structure, the collar end part was placed slightly outward from the side wall of the middle part of the arm body. Since it is necessary to secure a welding allowance by overhanging (for example, 7 mm), it is difficult to design the arm body itself to have a sufficient width cross section in the limited space around the middle part of the arm body. Thus, there are problems such as insufficient arm strength.

 In order to solve this problem, for example, as shown in FIG. 8 of Patent Document 2 below, a pair of left and right flanged brackets (half sleeves) are also inserted into both sides of the arm body, and the flanges are inserted into the arm body. Proposed improved technology to clear the strength requirements required by allowing the arm body itself to have a sufficient width cross-section in a limited space around the middle part of the arm body by superimposing and welding Has been.

 Patent Document 1: Japanese Patent Laid-Open No. 2002-337525

 Patent Document 2: Japanese Unexamined Patent Publication No. 2002-337524

 Disclosure of the invention

Problems to be solved by the invention However, in the suspension arm structure of Patent Document 1 described above, it is necessary to perform burring on both the upper end plate and the lower end plate that are respectively connected to one end of each of the upper plate and the lower plate that are press-formed. As a whole, the machining process with a large number of machining steps becomes complicated, and there is a problem that the productivity is poor and the machining cost is increased.

 [0009] In addition, the suspension arm needs to be further strengthened due to the increase in the horsepower of the automobile, the increase in the tire flattening ratio, etc., and the restriction on the space around the arm has increased, so it is necessary to further increase the holding strength around the bush. In this case, it is necessary to increase the plate thickness of the upper plate and lower plate. However, increasing the plate thickness increases the weight and cost, and increases the occupied space, greatly increasing the degree of freedom in layout. There is a risk of being restricted to.

 [0010] In addition, the strength of the suspension arm is generally different depending on the vehicle type variation (normal car, advanced car, sports type car), but the molds for molding the upper plate and the lower plate are usually common. However, it is difficult to cope with the setting of the plate thickness according to the strength condition, which increases the weight and cost for a normal vehicle.

 [0011] The present invention has been proposed in view of the above circumstances, and a part of the bush press-fit portion and the arm main body may be integrated, or an arm main body for constituting the bush press-fit portion. It is a first object of the present invention to provide a vehicle suspension arm that can solve the above-mentioned conventional problems with a simple structure even if the burring process is omitted.

[0012] On the other hand, in the suspension arm of Patent Document 2 described above, the front and rear input loads from the tires are particularly large due to further increase in wheel wheel diameter, further increase in engine output, etc., depending on the vehicle type. In some cases, it may be difficult to respond due to strength problems.

[0013] The present invention has been proposed in view of the above circumstances, and even if the arm body is constituted by a press-formed metal plate, the above-described conventional problem of the plate arm can be solved with a simple structure. A second object is to provide a suspension arm for a vehicle.

 Means for solving the problem

[0014] In order to achieve the first object, the present invention provides a suspension for a vehicle including an arm body and a bush press-fit portion provided at one end of the arm body and capable of press-fitting and fitting a bush. In the arm, the arm main body is press-molded to form a main part of the arm main body, and a main plate body in which a short cylindrical part is integrally connected to one end by burring, and a main plate body thereof. A reinforcing plate that is superposed on the upper and lower surfaces of the plate body and reinforces the main plate body, the reinforcing plate being formed in an annular shape and coaxially aligned with the short cylindrical portion, and the eyeball And a tail portion that extends integrally along the longitudinal direction of the main plate body from the shaped head, and is made of a thicker plate material than the main plate body, and at least the tail portion is welded to the main plate body. The first feature is that the bush press-fitting portion is constituted by the inner peripheral surface of the eyeball-shaped head and the inner peripheral surface of the short cylindrical portion.

[0015] Further, the present invention provides a vehicle suspension arm including an arm body and a bush press-fit portion provided at one end of the arm body and capable of press-fitting and fitting a bush. A main plate body that is press-molded to form a main portion of the arm main body, and an end-shaped end portion that is formed in an annular shape at one end, and is superposed on the upper and lower surfaces of the main plate body. At least a reinforcing plate that reinforces the body, the reinforcing plate being formed in an annular shape and coaxially aligned with the eyeball-shaped end portion, and the longitudinal direction of the main plate body from the eyeball-shaped head portion And a tail portion that extends integrally along the main plate body, and is formed of a plate material that is thicker than the main plate body, and at least the tail portion is welded to the main plate body. Or the inner peripheral surface of the eyeball-shaped head and the inner end of the eyeball-shaped end portion. The bush press-fit portion at the surface is a second aspect to be configured.

[0016] Further, the present invention provides a vehicle suspension arm including an arm main body and a bush press-fit portion provided at one end of the arm main body and capable of press-fitting and fitting a bush. Each of them is press-molded to form a main part, and further includes a hollow frame made of a combination of lower plate bodies, an eyeball-shaped head formed in an annular shape, and a tail that extends integrally from the eyeball-shaped head. At least one reinforcing plate to be inserted into and welded to a hollow portion at one end of the hollow frame body, and the reinforcing plate is formed of a plate material thicker than the upper and lower plate bodies. In addition, a third feature is that the bush press-fitting portion is configured by an inner peripheral surface of the eyeball-shaped head.

[0017] Similarly, in order to achieve the first object, in addition to the third feature of the present invention, the arm body includes an eyeball-shaped head formed in an annular shape and the eyeball-shaped head. The second reinforcing plate further includes a second reinforcing plate that has a tail portion that extends more integrally, and the tail portion is welded to the upper and lower surfaces of one end portion of the hollow frame body. Than the upper and lower plates A fourth feature is that the bush press-fitting portion is formed on the inner peripheral surface of the eyeball-shaped head of the second reinforcing plate while being formed of a thick plate material.

[0018] Further, in addition to the fourth feature, the tail portion of one of the reinforcing plates is formed longer than the tail portion of the other reinforcing plate! In the longitudinal direction of the upper and lower plate bodies The fifth feature is that it extends along the line.

[0019] Further, in addition to the first to fifth features, a sixth feature is that the reinforcing plate is formed by stamping a single plate material with a press.

[0020] Furthermore, in addition to the first or second feature, the reinforcing plate includes a positioning projection for positioning the reinforcing plate with respect to the main plate body in cooperation with a positioning hole provided in the main plate body. Alternatively, the seventh feature is that a hole is formed.

[0021] Furthermore, in addition to the third, fourth, or fifth feature, the reinforcing plate is provided with a reinforcing plate for the hollow frame body in cooperation with a positioning hole provided in the upper or lower plate body. The eighth feature is that a positioning protrusion or hole for positioning is formed.

[0022] Furthermore, in addition to the first, second, or third feature, the reinforcing plate includes only a ring portion that overlaps the eyeball-shaped head portion thereof and a part of the base portion side of the tail portion. A ninth feature is that a local reinforcing plate made of a plate material integrally having an overlapping tongue piece is joined in a laminated state, and the bush press-fitting portion is also formed on the inner peripheral surface of the ring portion.

[0023] Furthermore, in addition to the fourth feature, the second reinforcing plate includes a ring portion that overlaps the eyeball-shaped head portion of the second reinforcing plate, and a tongue piece that overlaps only a part of the base side of the tail portion. According to a tenth feature of the present invention, a local reinforcing plate made of a plate material that is integrally formed is coupled in a stacked state, and the bush press-fitting portion is also formed on the inner peripheral surface of the ring portion.

[0024] Furthermore, in addition to the ninth or tenth feature, by welding between an inner surface of a through-hole formed in the tongue piece and the tail portion where the tongue piece overlaps, An eleventh feature is that the local reinforcing plate and the reinforcing plate are coupled.

[0025] Further, in order to achieve the second object, the present invention includes a press-molded metal plate that is formed into a hollow body, one end is on the vehicle body side, and the other end is on the wheel side. A bush for fitting and supporting a connecting bush to a fork-like lower end of a damper straddling the arm body to be connected and an intermediate portion extending substantially in the vehicle width direction of the arm main body with a gap. A suspension arm for a vehicle, in which a drive shaft passes through the gap, and both end portions of the bush support sleeve are provided on the front side wall and the rear side wall of the intermediate portion of the arm body. A pair of front and rear sleeve holes to be fitted are formed, and welding margins are projected outward from the arm body to weld the sleeve and the arm body at both ends of the bush support sleeve. The provided intermediate portion of the arm body is formed in a generally trapezoidal shape with a transverse cross section that is longer than the upper wall, and the front and rear side walls are directed downward as a result of downward force. Corresponding to the cross-sectional shape of the arm body, the bush support sleeve is formed in a trapezoidal shape in side view so as to secure the welding margin, and further, the bush support sleeve is formed. The front and rear end surfaces of the groove are provided with reliefs for securing a clearance between the fork-like lower end and the sleeve when the fork-like lower end of the damper and the arm body are relatively displaced. First

With 12 features.

 [0026] Similarly, in order to achieve the second object, in addition to the twelfth feature of the present invention, the bush support sleeve is formed by pressing one end edge portion and the other end portion of a pressed plate-shaped sleeve material. A thirteenth feature is that the edge portions are wound into a cylindrical shape so as to be connected to each other, and the one end edge portion and the other end edge portion are welded together.

 [0027] Further, in addition to the twelfth or thirteenth feature, a simple cylindrical inner sleeve shorter than the sleeve is fitted and fixed to the inner peripheral surface of the bush support sleeve. The fourteenth feature is that the bush is fitted and supported by the bush support sleeve via the sleeve.

 [0028] Further, in consideration of any of the twelfth to fourteenth features, the pair of sleeve holes are each formed in a notch shape with an open top, and the upper wall of the arm body is provided with the upper wall. The fifteenth feature is that they communicate with each other through an opening provided so as to cross.

[0029] Further, in addition to the fifteenth feature, opposite inner surfaces of the opening are substantially perpendicular to an outer surface of the arm body, and are formed on both inner surfaces of the opening. Correspondingly, on the peripheral wall of the bush support sleeve, a pair of protrusions bulging radially outward of the sleeve are formed along the generatrix direction of the sleeve and spaced apart from each other in the circumferential direction. The sixteenth feature is that the gap between the protrusion and the inner surface of the opening is welded. To do.

 [0030] Furthermore, in addition to the sixteenth feature, a support bracket capable of holding a wheel support ball joint at the outer end is joined to the other end of the arm body along the longitudinal direction of the other end. A seventeenth feature is that the inner end portion of the support bracket is engaged and welded to an engagement recess formed in the protrusion.

 The invention's effect

 [0031] According to the first feature of the present invention, the arm main body is press-molded to form a main portion of the arm main body, and a main plate body integrally provided with a short cylindrical portion at one end by burring. A reinforcing plate that is superposed on the upper and lower surfaces of the main plate to reinforce the main plate, and the reinforcing plate is formed in an annular shape and has an eyeball-shaped head aligned coaxially with the short cylindrical portion; A tail portion extending integrally along the longitudinal direction of the main plate body from the eyeball-shaped head, and is formed of a plate material thicker than the main plate body, and at least the tail portion is formed on the main plate body. Since the bush press-fit portion is configured by the inner peripheral surface of the eyeball-shaped head and the inner peripheral surface of the short cylindrical portion that are welded, a portion of the bush press-fit portion and the arm body are seamlessly connected. It is advantageous to increase the strength because it can be connected integrally, and the above The strong plate sufficiently secures the cross-sectional shape of the transition portion from the bush press-fit portion to the plate arm body, and can easily secure the necessary rigidity and strength of the transition portion, and further forms the bush press-fit portion. The burring process can be performed only on one end of the main plate, and the calorie process can be simplified. This can contribute to the improvement of productivity and the reduction of processing cost. In addition, when the suspension arm is required to be further strengthened due to an increase in the horsepower of the automobile, etc., it is easy to increase the thickness of the reinforcing plate, and the extra force will increase the outer peripheral space of the bush press-fit part. It is possible to cope with the difference in the strength conditions of the suspension arm depending on the vehicle type variation, and it can be easily and inexpensively handled by changing the thickness of the reinforcing plate. In addition, since the bush press-fit portion is composed of the inner peripheral surface of the eyeball-shaped head of the reinforcing plate and the inner peripheral surface of the short cylindrical portion of the arm body that has been subjected to burring, a sufficient holding load on the bush can be secured, It is possible to omit or reduce the welded part between the arm body and the reinforcing plate around the press-fitted part.

[0032] Further, according to the second feature of the present invention, the arm body is press-molded to form the arm body. The main plate body has a main plate body with an eyeball-shaped end portion formed integrally with one end of the main plate body, and a reinforcing plate that is superposed on the upper and lower surfaces of the main plate body to reinforce the main plate body. The reinforcing plate is formed in an annular shape and extends integrally along the longitudinal direction of the main plate body from the eyeball-shaped head portion aligned with the eyeball-shaped end portion on the same axis. The tail plate is formed of a plate material thicker than the main plate, and at least the tail is welded to the main plate, at the inner peripheral surface of the eyeball head, or the eyeball head Since the bush press-fit portion is composed of the inner peripheral surface of the rim and the inner peripheral surface of the eyeball-shaped end, the reinforcing plate ensures a sufficient cross-sectional shape of the transition portion from the bush press-fit portion to the plate arm body, The required rigidity and strength of the transition portion can be easily secured, and the arm body and the bush press-fit portion While leaving the body structure parts, and can be omitted burring processing to form a bush press-fit portion, it is possible to contribute to saving of increased productivity and mosquito 卩 Ekosuto. In addition, when the suspension arm is required to be further strengthened due to an increase in the horsepower of the car, etc., it is easy to increase the thickness of the reinforcing plate, and the shirring also increases the outer space of the bush press-in part specially. In addition, it is possible to respond easily and at low cost by changing the thickness of the reinforcing plate even if the suspension arm strength conditions differ depending on the vehicle type variation. In particular, when the bush press-fit portion is composed of the inner peripheral surface of the eyeball-shaped head portion of the reinforcing plate and the inner peripheral surface of the eyeball-shaped end portion, a sufficient holding load for the bush can be secured, and the area around the press-fit portion can be secured. It is possible to omit or reduce the welded portion between the arm body and the reinforcing plate.

Further, according to the third feature of the present invention, the arm body is formed in an annular shape with a hollow frame made of a combined body of the lower plate bodies, each of which is press-molded as a main part of the arm body. It has an eyeball-shaped head and a tail that extends integrally from the eyeball-shaped head! The reinforcing plate is at least provided with a reinforcing plate that is inserted and welded into a hollow portion at one end of the hollow frame body, and the reinforcing plate is formed of a plate material thicker than the upper and lower plate bodies, Since the bush press-fit part is configured by the inner peripheral surface of the head, the reinforcing plate ensures a sufficient cross-sectional shape of the transition part from the bush press-fit part to the plate arm body, and the necessary rigidity of the transition part The strength can be easily secured, and the burring calorie for forming the bush press-fitting portion can be omitted, which can contribute to the improvement of productivity and the reduction of the caulking cost. Also If the suspension arm is required to be further strengthened due to an increase in the horsepower of the vehicle, etc., it can be handled simply by increasing the thickness of the reinforcing plate, and the force can be handled without any special increase in the outer peripheral space of the bush press-fit part. In addition, even if the suspension arm strength conditions differ depending on the vehicle type variation, it is possible to easily and at low cost by changing the thickness of the reinforcing plate.

 [0034] Further, in particular, according to the fourth feature, in addition to the third feature, the arm main body includes an eyeball-shaped head formed in an annular shape and a tail portion extending integrally from the eyeball-shaped head. Have it! In addition, the tail portion is further provided with a second reinforcing plate that is welded to the upper and lower surfaces of one end portion of the hollow frame body, and the second reinforcing plate is formed of a plate material thicker than the upper and lower plate bodies. In addition, since the bush press-fitting portion is also formed on the inner peripheral surface of the eyeball-shaped head of the second reinforcing plate, a sufficient holding load on the bush can be secured.

 [0035] Further, in particular, according to the fifth feature, in addition to the fourth feature, the tail portion of one reinforcing plate is formed longer than the tail portion of the other reinforcing plate, and the upper and lower plates Since it extends along the longitudinal direction of the body! /, It is possible to increase the bonding strength between the one reinforcing plate and the hollow frame body by its length and tail.

 [0036] Further, particularly according to the sixth feature, in addition to the first to fifth features, the reinforcing plate is formed by stamping a single plate material with a press. In addition to the excellent productivity of the reinforcing plate, the inner peripheral surface of the eyeball-shaped head that becomes the bush press-fit portion in the reinforcing plate can be easily formed by using the cut surface of the press punching, and the bush pressure The inner diameter accuracy required for insertion can be easily realized at low cost.

 [0037] Further, particularly according to the seventh or eighth feature, the reinforcing plate includes a reinforcing plate for the main plate body or the hollow plate body in cooperation with a positioning hole provided in the main plate body or the upper or lower plate body. Positioning protrusions or holes for positioning are formed, so even if the reinforcing plate is separated from the arm body, the reinforcing plate can be positioned accurately and easily with a simple positioning structure. .

[0038] Further, particularly according to the ninth or tenth feature, the reinforcing plate or the second reinforcing plate includes only a ring portion that overlaps the eyeball-shaped head portion thereof and a part of the base portion side of the tail portion. A local reinforcing plate made of a plate material integrally having overlapping tongue pieces is joined in a laminated state, and the inner peripheral surface of the ring portion is also connected. Since the bush press-fit part is configured, the increase in the thickness of the tail part of the reinforcing plate is suppressed as much as possible due to the lamination effect of the local reinforcing plate (i.e., while reducing the weight of the reinforcing plate). The bushing holding strength can be increased by effectively increasing the axial width, and the force of the reinforcing plate and the local reinforcing plate is reduced gradually from the bush press-fit part to the arm body side to make a smooth transition to the arm body section. be able to.

 [0039] Further, particularly according to the eleventh feature, the local reinforcing plate is welded by welding between an inner surface of a through-hole formed in the tongue piece and the tail portion where the tongue piece overlaps. And the reinforcing plate are combined, it is possible to reduce the weight of the local reinforcing plate while ensuring the necessary welding strength.

 [0040] Further, according to the twelfth feature of the present invention, the intermediate portion of the arm main body has a transverse cross section that is longer than the upper wall, and the front side wall and the rear side wall are directed downward, and generally spreads toward the end. Corresponding to the cross-sectional shape of the arm body, the bush support sleeve is formed in a generally trapezoidal shape in side view so as to secure a welding margin between the sleeve and the arm body. Therefore, against the large vertical input load acting on the arm body from the fork-shaped lower end of the damper via the sleeve and bush, and the large forward and backward input load (brake reaction force) from the tire In a limited space, it is possible to efficiently provide a sufficient width cross section in the middle part of the arm itself, and even a plate-structured arm body can secure sufficient strength. Also, on the front and rear end faces of the bush support sleeve, there is a clearance to ensure a clearance between the fork bottom end and the sleeve when the fork bottom end of the damper and the arm body are relatively displaced. Even if the side surface shape of the sleeve is a trapezoidal shape corresponding to the cross-sectional shape of the middle part of the arm body, there is a possibility that the rear end surface before and after the sleeve that spreads downward from each other may interfere with the fork-like lower end portion of the damper. Nah ...

[0041] Further, particularly according to the thirteenth feature, the bush support sleeve is formed by being wound into a cylindrical shape so as to connect one end edge portion and the other end edge portion of a pressed plate-shaped sleeve material. Since the one end edge portion and the other end edge portion are welded to each other, the front and rear end surfaces of the bush support sleeve are diverging downward in a side view as described above and have the relief. Even if it becomes a complicated line form due to the above, it can be accurately formed by simple press processing on the plate-like sleeve material, which contributes to improving the accuracy and efficiency of the machining process. Can give.

 [0042] Further, in particular, according to the fourteenth feature, a simple cylindrical inner sleeve shorter than the sleeve is fitted and fixed to the inner peripheral surface of the bush supporting sleeve, and the bush is interposed through the inner sleeve. Since the sleeve is fitted and supported by the bush support sleeve, the inner sleeve is arranged only in the part necessary for holding the bush even if the side surface of the sleeve is trapezoidal as described above (i.e. A double sleeve structure (which is omitted as much as possible) is obtained, and therefore the rigidity and strength of the sleeve can be sufficiently increased while reducing the weight of the sleeve. However, since the processing accuracy of the outer sleeve is relatively low compared to the inner sleeve that directly holds the bush, the cost of caloe can be saved.

 [0043] Further, particularly according to the fifteenth feature, the pair of sleeve holes respectively formed in the front and rear side walls of the arm body are formed in the shape of a notch with an open top, and are formed in the arm body. Since they communicate with each other through an opening provided across the upper wall, machining of the sleeve hole is relatively easy and cost savings are achieved, and part of the sleeve hole is projected. A relatively large diameter bush support sleeve can be used.

 [0044] Further, particularly according to the sixteenth feature, even if the inner side surface of the opening portion of the upper wall of the arm body is substantially perpendicular to the outer surface of the arm body for the convenience of processing, the opening portion A pair of protrusions bulging radially outward of the sleeve are formed along the generatrix direction of the sleeve and in the circumferential direction on the peripheral wall of the bush support sleeve corresponding to the inner surfaces of the sleeve. Since the protrusions are welded to the inner surface of the opening, the gap between the inner surface of the opening and the bush support sleeve (the protrusion) is formed. The gap can be reduced as much as possible, and the strength of the weld in the gap can be effectively increased.

[0045] In particular, according to the seventeenth feature, a support bracket capable of holding the wheel support ball joint at the outer end is joined to the other end of the arm body along the longitudinal direction of the other end. Since the inner end portion of the support bracket is engaged and welded to the engagement recess formed in the ridge portion, the ridge portion of the bush support sleeve is used to move the support bracket to the arm main body side. The weld area can be extended, and the strength of the connection of the support bracket to the arm body can be increased. Brief Description of Drawings

 FIG. 1 is a perspective view schematically showing a vehicle mounting state of an automobile suspension arm according to an embodiment of the present invention.

 FIG. 2 is a single perspective view of the suspension arm.

 FIG. 3 is a single plan view of the suspension arm.

 [FIG. 4] FIG. 4 is a bottom view of the suspension arm (viewed in the direction of arrow 4 in FIG. 2).

 FIG. 5 is an exploded perspective view of the suspension.

 FIG. 6 is an enlarged cross-sectional view taken along line 6-6 of FIG.

 FIG. 7 is an enlarged sectional view taken along line 7-7 in FIG.

 FIG. 8 is an enlarged sectional view taken along line 8-8 in FIG.

[9] FIG. 9 is a view corresponding to FIG. 8 showing a modification of the positioning structure of the reinforcing plate with respect to the arm body.

[10] FIG. 10 is a plan view showing a first modification of the first bush press-fitting portion.

 FIG. 11 is a cross-sectional view taken along line 11 11 of FIG.

[12] FIG. 12 is a plan view showing a second modification of the first bush press-fitting portion.

 FIG. 13 is a sectional view taken along line 13-13 of FIG.

 FIG. 14 is a cross-sectional view taken along line 14 14 of FIG.

15] FIG. 15 is a plan view showing a third modification of the first bush press-fitting portion.

 FIG. 16 is a cross-sectional view taken along line 16-16 of FIG.

 FIG. 17 is an enlarged view taken along arrow 17 in FIG.

 FIG. 18 is an enlarged sectional view taken along line 18-18 in FIG.

 FIG. 19 is a cross-sectional view taken along line 19 19 of FIG.

[20] FIG. 20 is a partial perspective view showing a modification of the winding forming structure of the bush support sleeve.

[21] FIG. 21 is a view corresponding to FIG. 17 showing a first modified example of the coupling structure of the bush support sleeve and the arm body.

 22 is a cross-sectional view taken along line 22-22 of FIG.

[23] FIG. 23 shows a second modification of the coupling structure between the bush support sleeve and the arm body. FIG. 18 is a diagram corresponding to FIG.

 FIG. 24 is a sectional view taken along line 24-24 in FIG.

25] FIG. 25 is a view corresponding to FIG. 15 showing another embodiment in which the local reinforcing structure for the reinforcing plate by adding the local reinforcing plate is applied to the third modification of the first bush press-fitting portion.

FIG. 26 is a cross-sectional view taken along line 26-26 in FIG.

27] FIG. 27 is an exploded perspective view of the other embodiment.

 [FIG. 28] FIG. 28 is a cross-sectional view of an essential part showing a connecting portion between a conventional suspension arm and a damper.

Explanation of symbols

 B1 1st rubber bush (bush)

 EB short cylinder

 EP Eyeball end

 H, Η 'Reinforcing plate

 Ha, Ha 'eyeball head

 Hb, Hb 'tail

 H Local footboard

 Ha "Ring

 H tongue

 LA Lower arm (suspension-arm)

 PI 1st bush press-fit part (Bush: Press-fit part)

 T hollow frame

 1 Arm body

 2 Upper plate (main plate)

 3 Lower plate

 100 Through hole

 BJ Ball support ball joint

 B3 3rd rubber bush (bush)

D Damba F Body or subframe

 J3 connecting pin

nf, nr escape

 LA Lower arm (suspension arm)

O opening

 P3 3rd bush press-fit part (bush press-fit part)

S Bushing support sleeve

 Sa one edge

 Sb other edge

 Sef

 Ser rear end face

 Sf, Sr welding allowance

 Sh engagement hole (engagement recess)

 St, St 'ridge

 SI inner sleeve

 S gap

w wheels

 1 Arm body

 Id middle part

 2 Upper plate (metal plate)

 3 Lower plate (metal plate, lower wall)

 7 Fork-shaped lower end

 10 Drive shaft

 2f Front side wall of front plate (front side wall)

2r Rear side wall of the upper plate (rear side wall)

2u Upper wall of upper plate (upper wall)

 2fh, 2rh Sleeve hole

4 Support bracket BEST MODE FOR CARRYING OUT THE INVENTION

 Embodiments of the present invention will be specifically described below based on examples of the present invention illustrated in the accompanying drawings.

 Example 1

 [0049] As shown in FIG. 1, the knuckle N that rotatably supports the wheel W of the wheel has a lower portion connected by a lower arm A and an upper portion thereof connected to the vehicle body by an upper arm (not shown) or a subframe connected thereto. (Hereinafter simply referred to as body F) so that it can move up and down. In addition, a damper D with a coil spring is interposed between the vehicle body F and the middle portion of the door arm A to support the weight of the vehicle body and cushion the vertical movement of the knuckle N.

 [0050] The lower arm A is a so-called A-type arm and constitutes the suspension arm of the present invention. The lower arm LA has an outer end connected to a knuckle N via a ball joint BJ so as to be able to swing, and a first and a second inner end divided into a bifurcated shape include a pair of front and rear rubber bushes. It is connected to the vehicle body F via Bl and B2 and connecting pins Jl and J2 penetrating them.

 [0051] Referring also to FIGS. 2 to 5, the arm body 1 of the lower arm LA is formed by integrally joining the upper plate body 2 and the lower plate body 3 formed by pressing each steel plate. The hollow frame body T is configured as a main part, and the arm center part force is also directed toward the outer end part to extend substantially in the vehicle width direction (that is, substantially in the left-right direction of the vehicle body). The first inner arm 1B that extends diagonally forward inward from the center toward the first inner end, and the second inner arm that extends diagonally backward inward from the center to the second inner end Part 1C. A first bush press-fit portion P1 for press-fitting and supporting the first rubber bush B1 to the inner periphery is provided at the front first inner end of the arm body 1, and a rear second inner end is provided at the first inner end of the arm body 1. A second bushing press-fit portion P2 for press-fitting and supporting the second rubber bush B2 on the inner periphery is provided in series, and a support bracket having an attachment hole for supporting the ball joint BJ at the outer end of the arm body 1 4 is welded.

The axis of the first bush press-fit portion P1 is set in a substantially vertical direction, and the second bush press-fit portion P 2 is set in a substantially front-rear direction of the vehicle body. The second bushing press-fit portion P2 is composed of a cylindrical metal collar C in the illustrated example. The upper plate body 2 and the lower plate body 3 are welded to the second inner end portions on the rear side.

[0053] The central force of the arm body 1 (ie, the outer arm portion 1A and the first and second inner arm portions IB, 1C) has a transverse cross section that is longer than the upper wall and has a front wall in the illustrated example. And the rear side wall is formed in a generally trapezoidal shape that widens toward the bottom. That is, the upper plate body 2 is formed in a substantially U-shaped cross section with a substantially flat upper wall portion, and a front wall portion and a rear wall portion that hang downward from the front and rear ends of the upper plate body. The lower plate 3 is formed in a flat plate shape so as to close the lower end opening of the upper plate 2, and is abutted and welded between the inner surfaces of the front and rear side walls of the upper plate 2. RU

Next, the structure of the first bush press-fit portion P1 in the lower arm LA will be described with reference to FIGS.

 [0055] The first inner arm portion 1B of the arm body 1 is an upper portion as a main plate body which is a main portion of the inner arm portion 1B and has a short cylindrical portion EB connected to the body at one end by a balancing process. A plate 2 and a lower plate pair 3 that is welded to the upper plate 2 to block the open lower surface thereof, and a single plate material that is superposed and welded to the upper surface of the upper plate 2 to reinforce the upper plate 2 And a reinforcing plate H.

 [0056] This reinforcing plate H is formed in an annular shape and is aligned with the short cylindrical portion EB coaxially with the eyeball-shaped head portion Ha, and extends along the longitudinal direction of the upper plate body 2 from the eyeball-shaped head portion Ha. It has a tail Hb that extends integrally, and is formed by stamping a steel plate thicker than the upper and lower plates 2 and 3 with a press. Then, at least the tail portion Hb of the reinforcing plate H is welded to the upper plate 2 over substantially the entire length. Note that the center of the reinforcing plate H and the short cylindrical portion EB of the upper plate 2 are not welded in the illustrated example, but may be welded as necessary.

 [0057] Thus, the first bush press-fitting portion P1 is constituted by the inner peripheral surface of the press-shaped head portion Ha and the inner peripheral surface of the short cylindrical portion EB subjected to burring. . Accordingly, the outer peripheral collar Blc of the first rubber bush B1 is fitted and held on the inner peripheral surface by sequential press-fitting from one axial side (the upper side in the illustrated example).

[0058] According to the structure of the first bush press-fit portion P1 as described above, since a portion of the press-fit portion P1 and the arm body 1 are connected seamlessly and integrally, In addition, the reinforcement plate H is provided with a long tail Hb along the longitudinal direction of the arm body 1 in a special manner. Therefore, the cross-sectional shape of the transition portion from the bush press-fit portion PI to the plate arm main body 1 can be sufficiently secured, and the necessary rigidity and strength of the transition portion can be easily secured. In addition, the burring process for forming the bush press-fit part P1 only needs to be performed on one end of the main plate (upper plate 2), so that the machining process can be simplified and productivity can be improved. The strike is saved.

 [0059] Also, if the lower arm LA is required to improve its strength by increasing the horsepower of the automobile, etc., it is easy to increase the thickness of the reinforcing plate H, and the force of the outer periphery of the bush press-fit portion P1 is reduced. It can be handled without any special increase, and even if the strength of the lower arm LA varies depending on the vehicle type variation, it can be handled easily and at low cost by changing the thickness of the reinforcing plate H. Furthermore, the first bush press-fit portion P 1 is configured by the inner peripheral surface of the eyeball-shaped head portion Ha of the reinforcing plate H and the inner peripheral surface of the short cylindrical portion EP that is subjected to burring of the arm main body 1. Sufficient holding load for the rubber bush B1 can be secured, and the welded portion between the arm body 1 and the reinforcing plate H around the press-fitted portion P1 can be omitted or reduced. In addition, since the reinforcing plate H is formed by stamping a single plate material with a press, the productivity of the reinforcing plate H that is separate from the arm body 1 is not only high, but also in the reinforcing plate H. The inner peripheral surface of the eyeball-shaped head Ha that becomes the bush press-fit part P1 can be easily formed using the cut surface of press punching, and the high inner diameter accuracy required for bush press-fitting can be easily realized at low cost. is there.

 [0060] In addition, the reinforcing plate H with respect to the upper plate 2 is cooperated with the positioning hole 2h provided in the upper plate 2 near the eyeball-shaped head Ha of the tail Hb of the reinforcing plate H. A positioning projection Hi for positioning H is formed. Therefore, even if the reinforcing plate H is separated from the arm body 1, the reinforcing plate H can be positioned accurately and easily with a simple positioning structure. In place of such positioning protrusions Hi, a positioning hole Ho is provided in the reinforcing plate H as shown in FIG. 9, and a jig J that fits into the hole Ho and the positioning hole 2h of the upper plate 2 is used. Then, try to perform positioning.

 Next, a first modification of the first bush press-fitting portion P1 in the lower arm LA will be described with reference to FIGS.

In this modification, the arm body 1 is press-molded to form a main part of the arm body 1. At the one end, an upper end plate 2 as a main plate having an eyeball-shaped end portion EP formed in an annular shape is superposed on the body, and the upper plate 2 is superposed on the upper surface of the upper plate 2 In addition, in the illustrated example, an eyeball-shaped end portion EP ′ press-formed in an annular shape is integrally connected to one end of the lower plate body 3 via the inclined connection portion 3k. And is superposed on the same axis as the center end EP of the upper plate 2.

 [0063] Then, as in the previous embodiment, the reinforcing plate H is formed in an annular shape and has an eyeball-shaped head Ha arranged coaxially with the short cylindrical portion, and the length of the upper plate 2 from the eyeball-shaped head Ha. It has a tail Hb that extends integrally along the direction, and is formed by stamping a steel plate thicker than the upper and lower plates 2 and 3 with a press. Of the reinforcing plate H, at least the tail portion Hb is welded to the upper plate 2 over substantially the entire length thereof. It should be noted that the center of the reinforcing plate H and the short cylindrical parts EP and ΕΡ 'of the upper and lower plates 2 and 3 are not welded in the example shown in the figure. It may be welded accordingly.

 [0064] And the inner peripheral surface of the eyeball-shaped head portion Ha press-molded or the same as the inner peripheral surface of the eyeball-shaped head portion Ha, the inner peripheral surface of the eyeball-shaped end portion EP, ΕΡ ' Constitutes the first bushing press-fit part P1. Accordingly, the outer peripheral collar Blc of the first rubber bush B1 is fitted and held on the inner peripheral surface by sequential press-fitting from one axial side (the upper side in the illustrated example).

 [0065] Further, the reinforcing plate H with respect to the upper plate 2 is cooperated with the positioning hole 2h provided in the upper plate 2 near the center H of the tail Hb of the reinforcing plate H. Positioning projection Hi for positioning H or positioning hole similar to Fig. 9 is formed.

 [0066] Thus, also in this first modified example, basically the same operation and effect as in the previous embodiment can be obtained, while leaving an integral structure portion of the arm body 1 and the bush press-fit portion P1, The burring force to the arm body 1 for forming the bush press-fitting portion P1 can be omitted, so that productivity can be improved and cost can be reduced.

 Next, a second modification of the first bush press-fit portion P 1 in the lower arm LA will be described with reference to FIGS.

[0068] In this modification, the arm main body 1 includes a hollow frame T which is a main part of the arm main body 1, and is a combined body of the lower plate bodies 2 and 3, and an eyeball-shaped head formed in an annular shape. Part Ha and the eyes It has a tail Hb that extends integrally from the ball-shaped head Ha, and the tail Hb is provided with a reinforcing plate H that is inserted into and welded to a hollow portion at one end of the hollow frame T. In the illustrated example, the tail Hb of the reinforcing plate H is fixed to the inner surface of the upper plate 2 (that is, engaged with the inwardly curved portion of the upper wall of the upper plate 2 and the left and right side walls. After the fixing, the upper plate 2 and the lower plate 3 are joined. The first bush press-fit portion P 1 is formed on the inner peripheral surface of the eyeball-shaped head Ha, and the outer peripheral force bar Blc of the first rubber bush B 1 is axially one side (in the illustrated example) It is fitted and held by press-fitting from the upper side.

 [0069] Also, in a vehicle that requires a large press-fitting holding load of the first bush press-fitting portion P1, such as a sports type vehicle, as shown by a chain line in FIGS. A head Ha ′ and a tail Hb ′ extending integrally from the eyeball-shaped head Ha ′, wherein the tail HI is welded to the upper surface of one end of the hollow frame T. A reinforcing plate H ′ may be further provided. In that case, the first bush press-fit portion PI is formed by the inner peripheral surfaces of the eyeball-shaped heads Ha, Hb; Ha ′, Hb ′ of both reinforcing plates H, H ′. Accordingly, the outer peripheral collar Blc of the first rubber bush B1 is fitted and held on the inner peripheral surface by sequential press-fitting from one axial side (the upper side in the illustrated example).

 [0070] In this second modification, the tail Hb of one reinforcing plate H inserted and welded into the hollow frame T is the tail Hb 'of the reinforcing plate H' outside the hollow frame T. In contrast to the second modified example, the tail Hb ′ of the reinforcing plate H ′ outside the hollow frame T is formed on the bottom of the hollow frame T. Fig. 15, Fig. 16 shows the force that is formed longer than the tail Hb of one of the reinforcing plates H that is inserted and welded into the hollow frame T and extends along the longitudinal direction of the hollow frame T. It is the 3rd modification shown.

 [0071] Thus, in the second and third modified examples, basically the same operation and effect as in the previous embodiment can be obtained, and the burring with respect to the arm main body 1 for forming the bush press-fit portion P1. Power can be omitted, and productivity can be improved and the cost of money can be reduced.

[0072] Although not shown in the second and third modifications, the eyeball heads of the tails Hb, HI of at least one of the reinforcing plates H, H 'are the same as in the previous embodiment. Positioning projections or holes for positioning the reinforcing plates H and H 'with respect to the hollow frame T in cooperation with positioning holes provided in the upper or lower plate bodies 2 and 3 are provided near the portions Ha and H. You can form Yes.

 [0073] Next, a connection structure between the lower arm LA and the damper D will be described with reference to FIGS.

 [0074] A fork-like lower end portion 7 of the damper D spans the intermediate portion Id near the outer end serving as the damper support portion of the arm main body 1 (the outer arm portion 1A in the illustrated example) across the gap S. But the bottom

 D

 It is connected via a connecting pin J3 that is horizontally mounted on the end portion 7 and extends substantially in the front-rear direction of the vehicle body, and a third rubber bush B3 that surrounds the pin J3. A substantially cylindrical bush supporting sleeve S for press-fitting and supporting the third rubber bush B3 to the intermediate portion Id is attached to the intermediate portion Id of the arm body 1. Further, the gap S has a drive shaft for driving wheels.

 D

 10 or a protective boot PB covering the joint portion of the shaft 10 is disposed so that the outer end of the shaft 10 is connected to the wheel W of the wheel so as to rotate integrally.

 [0075] The intermediate portion Id extending in the vehicle width direction of the arm main body 1 (outer arm portion 1A) has an upper wall (upper wall portion 2u of the upper plate 2) in the same manner as the other portions of the arm main body 1. The lower wall (lower plate body 3) is longer and the front side wall (front side wall portion 2 f of the upper plate body 2) and the rear side wall (rear side wall portion 2 r of the upper plate body 2) are directed downward to form a broad base. It is formed into a shape. The front side wall 2f and the rear side wall 2r are formed with a pair of front and rear sleeve holes 2fh and 2rh for fitting the front and rear ends of the bush support sleeve S, respectively. In order to weld the sleeve S and the arm body 1, welding margins Sf, Sr are provided at the front and rear ends of the arm so as to slightly protrude outward from the arm body 1. Accordingly, the bush support sleeve S is formed in a substantially trapezoidal shape in a side view so as to ensure the necessary welding margins Sf and Sr corresponding to the cross-sectional shape of the arm body 1.

[0076] In this way, the cross-sectional shape force of the intermediate portion Id of the arm body (outer arm portion 1A) is formed in a generally trapezoidal shape in which the lower wall is longer than the upper wall and the front side wall and the rear side wall expand downward. Corresponding to the cross-sectional shape of the intermediate part Id of the arm main body, the bush support sleeve S is substantially trapezoidal in side view so as to secure the welding margins Sf, Sr between the sleeve S and the arm main body 1. Large input load acting on the arm body 1 from the fork-like lower end 7 of the damper D via the sleeve S and the bush B 3 and a large input load in the front-rear direction from the wheel W ( The middle part of the arm in a limited space against the brake reaction force) It is possible to efficiently design a cross section with a sufficient width, and the arm body with a plate structure

Even if it is 1, sufficient strength can be secured.

 [0077] Further, the front and rear end surfaces Sef, Ser of the bush support sleeve S are formed on the fork-shaped lower end portion 7 of the damper D and the arm body 1 as shown in FIG. Concave-curved reliefs nf and nr are formed between the lower end 7 and the sleeve S so as to secure the necessary minimum clearance. As a result, even if the side surface of the sleeve has a trapezoidal shape corresponding to the cross-sectional shape of the arm body 1 as described above, the front and rear end surfaces Sef and Ser of the endlessly expanding sleeve interfere with the fork-like lower end 7 of the damper D. There is no fear of it.

 In the illustrated example, the bush support sleeve S is formed by winding into a cylindrical shape so as to connect one end edge Sa and the other end edge Sb of a pressed plate-like sleeve material. The one end edge Sa and the other end edge Sb are butt welded. Therefore, the front and rear end surfaces Sef, Ser of the bush support sleeve S have a complicated line configuration due to the lower end of the lower end S in a side view and the reliefs nf, nr as described above. Even so, the complicated line form can be formed with high accuracy by simple press processing on the plate-shaped sleeve material, and the accuracy and efficiency of the processing process can be improved.

 Further, in the illustrated example, notch-shaped concave portions facing each other are formed between the opposing surfaces of the one end edge portion Sa and the other end edge portion Sb of the bush support sleeve S that face each other. A through hole Sk extending over the opposing surface is formed by both the concave portions. Then, the inner surface of the through-hole Sk and the outer peripheral surface of the inner sleeve SI exposed through the through-hole Sk are welded to increase the coupling strength between the sleeves S and SI, and the one end edge portion Sa. In addition, the bond strength between the other edge Sb can be increased.

[0080] The method of winding the bush support sleeve S and joining the end edges Sa and Sb is not limited to the illustrated example. For example, the through hole Sk is omitted and both end edge portions Sa are omitted. Therefore, butt welding may be performed over the entire area between the opposing faces of Sb. Further, instead of the butt welding as described above, both edge portions Sa and Sb of the plate sleeve material partially overlap each other in the sleeve radial direction as shown in FIG. 20, and the overlap portion is welded. You may do so. In this case, as shown in Fig. 20 (a), only the edge of the overlap portion may be simply welded, and further, as shown in Fig. 2 (b), A hole 10 is formed in advance at one end edge Sa, and the inner peripheral surface of the hole 10 and the other end edge Sb are welded together.

 In the illustrated example, a simple cylindrical inner sleeve SI shorter than the sleeve S is fitted and welded to the inner peripheral surface of the bush support sleeve S. 3 Bush B3 is press-fitted and fitted into the bush support sleeve S. According to such a double structure of the sleeves S and SI, even if the side surface form of the bush support sleeve S is trapezoidal as described above, the inner sleeve SI is disposed only at a portion necessary for holding the bush (that is, Since a double-sleeve structure (which eliminates waste as much as possible) can be obtained, the rigidity of the sleeves S and SI as a whole can be sufficiently increased while achieving light weight. However, since the processing accuracy of the outer sleeve S is relatively low as compared with the inner sleeve SI that directly holds the bush B3, it is possible to save the cost.

 By the way, the pair of sleeve holes 2fh and 2rh are each formed in the shape of a notch with an open top in the illustrated example, and are provided in the arm body 1 (upper plate 2) so as to cross the upper wall. Communicating with each other through the opening O. This makes it possible to use a relatively large-diameter bush support sleeve S that partially protrudes from the sleeve holes 2fh and 2rh, and forms the sleeve holes 2fh and 2rh and the opening O by pressing. Alternatively, forming by combining press processing and plasma cut processing, etc., makes processing work relatively easy and reduces costs.

Further, as shown in FIG. 17, on the inner side surface of the opening O of the upper wall of the arm body 1 (upper plate 2), the opening O is formed by press or plasma cutting or the like. In relation to this, the surface is substantially orthogonal to the outer surface of the arm body 1. Therefore, when the outer peripheral surface of the bush support sleeve S is a simple cylindrical surface, a V-shaped gap that is relatively large and wide is formed between the inner surface of the opening O and the outer peripheral surface of the bush support sleeve S. This is disadvantageous in increasing the weld strength of the weld in the gap. In the present embodiment, however, a pair of protrusions bulging outwardly in the radial direction of the sleeve S are formed on the peripheral wall of the bush support sleeve S corresponding to the opposite inner surfaces of the opening O, respectively. St, St 'are formed along the generatrix direction of the sleeve S and spaced apart from each other in the circumferential direction, whereby the inner surface of the opening O and the bush support sleeve S (St, St ') The V-shaped gap between the two can be reduced as much as possible, so that the weld strength of the welded portion in the gap can be effectively increased.

 Further, as described above, the support bracket 4 capable of holding the wheel support ball joint BJ is joined to the outer end portion of the arm body 1 (outer arm portion 1A) along the longitudinal direction of the other end portion. This support bracket 4 is, in the illustrated example, an eyeball-shaped head 4a on the outer end side that can hold the ball joint BJ, and an inner end that extends along the longitudinal direction of the arm body 1 from the eyeball-shaped head 4a. The tail 4b is formed integrally. The upper edge portion of the tail portion 4b is provided on the upper wall portion 2u of the upper plate 2 and one end is fitted and welded to the slit portion 2us communicating with the opening O. On the other hand, the tail portion 4b The lower edge portion is fitted and welded to a slit portion 3 s provided in the lower plate 3.

 [0085] Further, the inner end side of the tail portion 4b is formed in a fork shape that is bifurcated into upper and lower parts, and the upper end of the inner end is formed on one protrusion St provided on the outer periphery of the bush support sleeve S. It is inserted and welded into the engagement hole Sh as the formed engagement recess. By using the protrusion St of the bush support sleeve S in this way, the welding area of the support bracket 4 to the arm body 1 side can be extended, and the coupling strength of the support bracket 4 to the arm body 1 can be increased. In addition, the coupling strength of the bush support sleeve S can be increased.

 Next, referring to FIGS. 21 and 22, a first modification of the coupling structure between the bush support sleeve S and the arm body 1 will be described. In this modification, a pair of front and rear sleeve holes 2fh and 2rh provided in the front and rear side wall portions of the intermediate portion Id of the arm body 1 are formed as circular holes instead of notch holes. The bush support sleeve S having a circular cross section (and thus the pair of protrusions St and St 'on the outer periphery of the sleeve is omitted) is fitted and welded to the sleeve holes 2fh and 2rh, and the sleeve S An inner sleeve SI similar to the previous embodiment is fitted and welded to the inner peripheral surface. Also in this embodiment, the shapes of the front and rear end surfaces Sef, Ser of the bush support sleeve S are formed in the same manner as in the previous embodiment.

Next, referring to FIGS. 23 and 24, a second modification of the coupling structure between the bush support sleeve S and the arm body 1 will be described. In this modified example, the inner sleeve SI is omitted from the structure of the first modified example, and the third rubber bush B3 is directly press-fitted and held on the inner peripheral surface of the bush supporting sleeve S. The structure has been simplified. Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various small design changes can be made.

For example, in the above-described embodiment, the present invention may be applied to, for example, an I-type arm or an upper arm other than the A-type force indicating the A-type lower arm LA as the suspension arm.

 In the embodiment, the upper plate 2 and the lower plate 3 constituting the arm body 1 are connected by welding. However, in the present invention, the upper plate 2 and the lower plate are combined. The body 3 may be joined by fixing means other than welding!

 In the above embodiment, the bush support sleeve S is manufactured by winding a plate material into a cylindrical shape. However, both ends of an endless circular tube material are machined into a predetermined shape to make a bush. You can also make a support sleeve S.

 In the above-described embodiment, only the reinforcing plate H and only the reinforcing plate H and the second reinforcing plate H ′ are connected to the arm body 1 in order to constitute the first bush press-fitting portion P1. In the ninth to eleventh features of the present invention, in one or both of the reinforcing plate H and the second reinforcing plate H ′, a local portion that reinforces the peripheral portion of the first bush press-fit portion P1 with priority. An example in which the local reinforcing structure of the reinforcing plates H and H ′ by the local reinforcing plate H〃 may be combined in a laminated state is implemented in the third modification shown in FIGS. 15 and 16. 25 to 27. That is, the local reinforcing plate H "includes an annular ring portion Ha" that overlaps the eyeball-shaped head portions Ha and Ha 'of the reinforcing plates H and H', and the reinforcing plates H and H. It consists of a press-formed steel plate that has a tongue piece Hb〃 that overlaps only part of the base side of HI's tail Hb and HI, and is stacked on the reinforcing plates H and H '. The first bush press-fit portion PI is also formed by the inner peripheral surface of the ring portion Ha "of the local reinforcing plate H". The tongue piece Hb〃 is A through hole 100 penetrating in the direction is formed, and the inner surface of the hole 100 is welded to the tail portions Hb and Hb 'where the tongue pieces Hb〃 are superposed. And the reinforcing plates H and H '.

[0093] Thus, in this embodiment, the increase in the thickness of the tail portions Hb, Hb 'in the reinforcing plates H, H' is suppressed as much as possible by the lamination effect of the local reinforcing plates H "(that is, the reinforcing plates H, The bush holding strength is increased by effectively increasing the axial width of the bush press-fit part P 1 The entire cross section of the reinforcing plates H, H 'and the local reinforcing plate H "can be made thinner gradually from the bush press-fit portion P1 to the arm body 1 side, and smoothly transferred to the arm body cross section. Such a local reinforcing structure of the reinforcing plate H using the local reinforcing plate H ″ can also be implemented in the embodiments shown in FIGS. 6 to 9 and the modified examples shown in FIGS.

Claims

The scope of the claims  [1] A vehicle suspension arm comprising an arm body (1) and a bush press-fit portion (P1) provided at one end of the arm body (1) and capable of press-fitting and fitting a bush (B1). The main body (1) is a main plate body (2) which is press-molded to form a main portion of the arm main body (1) and has a short cylindrical portion (EB) continuously connected to one body by burring at one end, and the main plate A reinforcing plate (H) that is superposed on the upper and lower surfaces of the body (2) to reinforce the main plate (2), and  The reinforcing plate (H) is formed in an annular shape and aligned with the short cylindrical portion (EB) coaxially with the eyeball-shaped head (Ha), and from the eyeball-shaped head (Ha), the main plate (2) A tail portion (Hb) that extends integrally along the longitudinal direction, is thicker than the main plate (2), is formed of a plate material, and at least the tail portion (Hb) Welded to the main plate (2),  The suspension arm for a vehicle, wherein the bush press-fit portion (P1) is constituted by an inner peripheral surface of the eyeball-shaped head (Ha) and an inner peripheral surface of the short cylindrical portion (EB). [2] A vehicle suspension arm comprising an arm body (1) and a bush press-fit portion (P1) provided at one end of the arm body (1) and capable of press-fitting and fitting a bush (B1). The main body (1) is a main plate body (2) which is press-molded to form a main part of the arm main body (1) and has an eyeball-shaped end (EP) formed in an annular shape at one end. And at least a reinforcing plate (H) that is superposed on the upper and lower surfaces of the main plate (2) to reinforce the main plate (2),  The reinforcing plate (H) is formed in an annular shape and has an eyeball-shaped head (Ha) aligned coaxially with the eyeball-shaped end (EP), and a main plate body (2) from the eyeball-shaped head (Ha). ) And a tail portion (Hb) that extends integrally along the longitudinal direction of the main plate body (2) and is formed of a thicker plate material than the main plate body (2), and at least the tail portion (Hb). Is welded to the main plate (2),  The bush press-fit portion (P1) is formed on the inner peripheral surface of the eyeball-shaped head (Ha) or between the inner peripheral surface of the eyeball-shaped head (Ha) and the inner peripheral surface of the eyeball-shaped end portion (EP). A suspension arm for a vehicle, comprising: [3] In a vehicle suspension arm comprising an arm body (1) and a bush press-fit portion (P1) provided at one end of the arm body (1) and capable of press-fitting and fitting a bush (B1), The arm body (1) is press-molded so as to form a main part of the arm body (1), and further includes a hollow frame (T) composed of a combined body of the lower plate bodies (2, 3), and an annular shape. And the tail (Hb) extending integrally from the eyeball-shaped head (Ha), the tail (Hb) being the hollow frame (T And at least a reinforcing plate (H) to be inserted and welded into the hollow portion at one end of  The reinforcing plate (H) is formed of a plate material thicker than the upper and lower plate bodies (2), and the bush press-fitting portion (P1) is formed on the inner peripheral surface of the above-mentioned head-shaped head (Ha). A suspension arm for a vehicle characterized by [4] The arm body (1) has an eyeball-shaped head (H) formed in an annular shape and a tail (Hb ′) extending integrally from the eyeball-shaped head (Ha ′). The tail (Hb ′) is further provided with a second reinforcing plate (′) welded to the upper and lower surfaces of one end of the hollow frame (T).  The second reinforcing plate (Η ′) is formed of a plate material thicker than the upper and lower plate bodies (2, 3), and the eyeball-shaped head portion (2) of the second reinforcing plate (Η ′). 4. The suspension arm for a vehicle according to claim 3, wherein the bush press-fitting portion (P1) is also formed on the inner peripheral surface of (ii).  [5] The tail (Hb, Hb ') of one of the reinforcing plates (Η, H') is formed longer than the tail (HI, Hb) of the other reinforcing plate (Η ', Η) The vehicle suspension arm according to claim 4, wherein the suspension arm extends along the longitudinal direction of the hollow frame (T).  [6] The vehicle suspension according to any one of claims 1 to 5, wherein the reinforcing plate (H, H ') is formed by stamping a single plate material with a press. arm.  [7] The reinforcing plate (H, H ′) is provided on the reinforcing plate (H, H ′) with respect to the main plate (2) in cooperation with a positioning hole (2h) provided in the main plate (2). The vehicle suspension arm according to claim 1 or 2, wherein a positioning projection (Hi) or a hole (Ho) is formed to perform positioning of the vehicle. [8] The reinforcing plate (H, H ′) has a reinforcing plate (H, H ′) for the hollow frame (T) in cooperation with the positioning hole provided in the upper or lower plate (2, 3). ') Positioning protrusion for positioning 6. The vehicle suspension arm according to claim 3, 4 or 5, wherein a raising protrusion (Hi) or a hole (Ho) is formed.  [9] The reinforcing plate (H) has a ring portion (Ha ") that overlaps the eyeball-shaped head (Ha) of the reinforcing plate (H), and a tongue piece that overlaps only a part of the base side of the tail (Hb) ( The local reinforcing plate (H〃) made of a plate material integrally having Hb ") is joined in a laminated state, and the bush press-fit portion (P1) is also formed on the inner peripheral surface of the ring portion (Ha"). The vehicle suspension arm according to claim 1, 2 or 3, characterized by the above-mentioned.  [10] The second reinforcing plate (Η ′) includes a ring portion (Ha ″) that overlaps the eyeball-shaped head portion (Η) of the second reinforcing plate and a part on the base side of the tail portion (Hb ′). A local reinforcing plate (H〃) made of a plate material integrally having a tongue piece (Hb ") that overlaps with each other is joined in a laminated state, and the bush press-fit portion (PI) is also formed on the inner peripheral surface of the ring portion (Ha"). The vehicle suspension arm according to claim 4, wherein the vehicle suspension arm is configured.  [11] Weld the gap between the inner surface of the through hole (100) formed in the tongue piece (Hb〃) and the tail (Hb, HI) where the tongue piece (Hb〃) overlaps. The vehicle suspension arm according to claim 9 or 10, wherein the local reinforcing plate (H () and the reinforcing plate (H, H ') are coupled by welding.  [12] Arm body (1) which is formed into a hollow body from the press-formed metal plates (2, 3) and has one end connected to the vehicle body (F) side and the other end connected to the wheel (W) side. ) And an intermediate part (Id) extending substantially in the vehicle width direction of the arm body (1) with a gap (S) across the damper (D)  D  A bushing support sleeve (S) for fitting and supporting the connecting bush (B3) to the oak-like lower end (7) is provided, and the drive shaft (10) passes through the gap (S).  D  A suspension arm for a vehicle,  A pair of front and rear sleeve holes (2fh, 2rh) for fitting both ends of the bush support sleeve (S) to the front side wall (2f) and rear side wall (2r) of the intermediate part (Id) of the arm body (1) Are formed on the both ends of the bush support sleeve (S), and welding arm (Sf, Sr) force is used to weld the sleeve (S) to the arm body (1). (1) In what is provided to protrude outward, The intermediate part (Id) of the arm body (1) has a lower cross section in the lower wall (3) than the upper wall (2u). In addition, the front side wall (2f) and the rear side wall (2r) are formed in a generally trapezoidal shape that spreads toward the bottom by force.  Corresponding to the cross-sectional shape of the arm body (1), the bush support sleeve (S) is formed in a trapezoidal shape in a side view so as to secure the welding margin (Sf, Sr),  Further, the front and rear end surfaces (Sef, Ser) of the bush support sleeve (S) are formed in the fork-like shape when the fork-like lower end (7) of the damper (D) and the arm body (1) are relatively displaced. A suspension arm for a vehicle, characterized in that reliefs (nf, nr) are formed between the lower end (7) and the sleeve to secure clearance.  [13] The bush support sleeve (S) is formed by winding into a cylindrical shape so that one end edge (Sa) and the other end edge (Sb) of a pressed plate-shaped sleeve material are connected to each other. 13. The vehicle suspension arm according to claim 12, wherein the one end edge (Sa) and the other end edge (Sb) are welded to each other.  [14] A simple cylindrical inner sleeve (SI) shorter than the sleeve (S) is fitted and fixed to the inner peripheral surface of the bush supporting sleeve (S). The vehicle suspension arm according to claim 12 or 13, wherein the bush (B3) is fitted and supported by a bush support sleeve (S).  [15] The pair of sleeve holes (2fh, 2rh) are each formed in a notch shape with an open top, and are provided in the arm body (1) so as to cross the upper wall (2u). The vehicle suspension arm according to any one of claims 12 to 14, wherein the suspension arm is in communication with each other through an opening (O).  [16] The opposite inner surfaces of the opening (O) are substantially perpendicular to the outer surface of the arm body (1), and correspond to the inner surfaces of the opening (O), respectively. Then, on the peripheral wall of the bush support sleeve (S), there is a pair of ridges (St, St ′) bulging radially outward of the sleeve (S) in the direction of the generatrix of the sleeve (S) And are spaced apart from each other in the circumferential direction, and the gaps between the ridges (St, St ') and the inner surface of the opening (O) are welded. The vehicle suspension arm according to claim 15. [17] A support bracket (4) capable of holding the wheel support ball joint (BJ) at the outer end is joined to the other end of the arm body (1) along the longitudinal direction of the other end. This support bracket The vehicle suspension arm according to claim 16, wherein the inner end of (4) is engaged and welded to an engagement recess (Sh) formed in one of the protrusions (St). .